I have a 93 honda accord D4 flashes and car wont start only until it stops flashing it will start some times it takes a minute of flashinng and other times one hour or more after flashingstops car will start and run like normal but if i turn it off d4 might start flashing .

 

Short the service check connector (2-wire blue connector) under the glove box, turn keyswitch to ON, and read the flashes on the D4 light. See DIY library for links to how to intrepret the flashes. Post result and someone should be able to provide an understanding of the problem.

good luck

 

My dad's tranny recently went out. His car did the same. His D4 light flashed but it was already running. I might try checking the fluid and the code you pull, or you can take it to a shop although that's gonna cost you.

(PS: My dad's tranny worked fine later that day. I took it out for a drive and it seemed perfectly normal)